angular.merge fails with MediaStream objects

[matthieusieben]

Do you want to request a feature or report a bug?
Bug

What is the current behavior?
angular.merge transforms MediaStream objects in src into plain JavaScript Objects.

If the current behavior is a bug, please provide the steps to reproduce and if possible a minimal demo of the problem via https://plnkr.co or similar (template: http://plnkr.co/edit/tpl:yBpEi4).

With the template: https://plnkr.co/edit/4cBUxjdB4kya0s5Wtbxd?p=preview
Simpler: https://plnkr.co/edit/LGUAcCTbYyf4UTxSbvBC?p=preview

navigator.mediaDevices.getUserMedia({ audio: true }).then(function (stream) {
  var dst = angular.merge({}, { stream: stream });
  console.error('Is valid ?', stream === dst.stream); // false
})

What is the expected behavior?
angular.merge (and derived) should not alter MediaStream objects.

What is the motivation / use case for changing the behavior?
Allow writing simpler/cleaner code. The workaround is simply to manually set the stream objects.

Which versions of Angular, and which browser / OS are affected by this issue? Did this work in previous versions of Angular? Please also test with the latest stable and snapshot (https://code.angularjs.org/snapshot/) versions.

Google Chrome - Version 51.0.2704.106 (64-bit)
Other browsers probably also affected.

Other information (e.g. stacktraces, related issues, suggestions how to fix)
MediaStream objects should be cloned properly (MDN: MediaStream.clone()) in the case of angular.clone, or copied as is in angular.merge and angular.extend.

[Narretz]

The angular.* helpers are mainly designed for the uses of Angular core, so we don't usually prioritize fixing bugs in them. Pull requests are welcome nevertheless.

[matthieusieben]

The issue still exists with angular.clone

[gkalpak]

What is angular.clone?

[matthieusieben]

Il meant, angular.copy, sorry you were not able to figure that out...

[Narretz]

Sorry you were not able to make yourself clear ... :D

So for copy this should probably be fixed as copy is used by scope.$watch
For extend ... maybe, because that's used in route where it extends the params object.

[Narretz]

Actually, I can't see that extend is broken: https://plnkr.co/edit/B3LebuAQPoj6kRgS2eCG?p=preview

I created an issue for copy:
#16055